Need help booking?
Unpublished phone-only deals available
DEC to ALN: distance & flight time
Decatur (Decatur Airport) → Alton/St Louis (St Louis Regional Airport)
91 mi
146 km · 79 nm
42m
estimated nonstop flight time
—
time difference · heading southwest
See live DEC→ALN fares Phone-only fares on this route — call free
Flight time details
91 miles nonstop takes roughly 42m gate to gate, flying southwest. Add 45–90 minutes per connection if there's no nonstop service. Both airports share the same local time, so schedules read exactly as flown.
The two airports
- DEC — Decatur Airport · Decatur, United States
- ALN — St Louis Regional Airport · Alton/St Louis, United States
Distances are great-circle ("as the crow flies") — the same basis airlines use for frequent-flyer miles.
Alternate airports can cut this fare
Flying from or into a nearby airport is the #1 trick our agents use to beat online prices. Call and we'll compare every combination on one call.
Near DEC
Near ALN
- STL · St Louis Lambert International Airport20 mi away
- BLV · Scott AFB/Midamerica Airport26 mi away
- SUS · Spirit of St Louis Airport36 mi away
- SPI · Abraham Lincoln Capital Airport69 mi away
Frequently asked questions
How far is DEC from ALN?
The flight distance from Decatur (DEC) to Alton/St Louis (ALN) is 91 miles (146 km, 79 nautical miles), measured along the great-circle route airlines actually fly.
How long is the flight from DEC to ALN?
A nonstop flight takes about 42m gate to gate. Actual time varies with winds, routing and season — eastbound transatlantic flights, for example, are usually faster than the return.
What is the cheapest way to fly from DEC to ALN?
Compare live fares online, then call CheapoTrav — our agents have unpublished consolidator fares on DEC–ALN that never appear on search engines, with no booking fees.